Tufting machine pattern means using infrared radiation detectors



M y 3, 969 R EELUSON Em. 3,442 535 TUFTING MACHINE PATTERN MEANS USINGINFRARED RADIATION DETECTORS Filed March 28, 1966 QoNALP E. ELL/50H TENNFRI'QHARD mvsmbas:

prIZM ArraKuEY United States Patent 3 443 535 TUFTING MACHlNE PA fTERNMEANS USING INFRARED RADIATION DETECTORS I Ronald E. Ellison, Langho,and John Pritchard, Rishton,

U.S. Cl. 112-79 3 Claims ABSTRACT OF THE DISCLOSURE A device forcontrolling a supply of yarn to the needles of a pattern-producingtufting machine comprising a pattern moved synchronously with thematerial made by the machine, and having infrared reflecting andabsorbing areas, a row of lamps located to supply said pattern withinfrared radiation, light guides positioned between said lamps and saidpattern, filters for passing only infrared radiation, positioned betweensaid light guides and said lamps, a plurality of infrared sensitivecells and means mounting said infrared sensitive cells in said lightguides adjacent said pattern, whereby infrared light passes through saidlight guides and is reflected from said infrared reflecting areas intosaid infrared sensitive cells.

Our invention relates to tufting machines for making carpets and liketextile articles, and has for its object the provision of means forproducing a pattern effect. The said effect consists in the productionof tuft loops of different lengths, and may include the production of acoloured pattern.

It is known to provide each yarn or a group thereof with an individualcontrol for effecting the length of each loop made by the needles, thecontrol being derived by a photocell such as a phototransistor providedfor each yarn or group, a row of such cells being located on one side ofa translucent drum having an opaque pattern thereon, with a light sourceinside the drum, which is rotated at a predetermined rate relative tothe photocells so as to control the tufts produced in accordance withthe pattern. This arrangement has the disadvantages that the patterndrum must be shielded from room light, and that the energy falling oneach photocell is relatively small. These devices are disclosed in U.S.Patent No. 3,103,187 issued to W. W. Hammel, Jr., on Sept. 10, 1963 andU.S. Patent No. 3,262,163 issued on Sept. 13, 1966 to I. O. Erwin, Jr.,et al.

We propose to avoid or reduce these disadvantages by the use of infraredradiation for pattern control, rather than visual light. By this means,a considerably greater quantity of energy is available for controlpurposes, and the system becomes less liable to disturbance by incidentlight, such as daylight, which usually has a low infrared component.

In an embodiment of our invention, a tufting machine with individual orgroup needle control is provided with a pattern of infrared reflectingand infrared absorbing areas, the pattern being in the form of anendless band carried between two forwarding rollers. A line source ofinfrared radiation, which may be a row of ordinary small electric lightbulbs, is located near the band, and a row of infrared responsivephotocells is also thus located. The said cells or lamps may be providedwith infrared filters, as this is advantageous in preventinginterference with pattern control by stray light. Each photocell isconnected to an implifier-rectifier the output of which operates aPatented May 13, 1969 control mechanism operating on one or more yarns,to control their tuft lengths.

In operation, the pattern is traversed past the photocells at a speedcommensurate with the rate of action of the needles of the machine, thusforming a pattern of long and short loops. The amplifiers may be adaptedto exercise their control function either in the presence or the absenceof infrared reception, so that the pattern effect on the needles can bereversed.

Finally, the pattern may consist of areas of infrared transmitting andinfrared absorbing materials, with the photocells energised by radiationtransmitted through the pattern 1 in which case the infrared-source islocated inside a pattern drum round which the pattern is laid.

According to our invention, a tufting machine is provided with a patternconstructed to transmit or reflect infrared radiation inpattern-defining areas, the said pattern being moved past a source ofinfrared radiation and a plurality of infrared sensitive photocells eachof which exercises a control function on one or more yarns.

Reference should now be made to the accompanying drawings, in which:

FIG. 1 is an end view of a pattern control device according to ourinvention, and

FIG. 2 is a portion of a pattern.

From FIG. 1 it will be seen that a pattern control device comprises anendless band pattern I wound round two rollers 2, 3, one of which isdriven (No. 2), the other being a tensioning or jockey roller. Aboveroller 2 is a radiation conductor 13, drilled to take a plurality ofphotocells such as 4, these having a maximum sensitivity, to infraredradiation. The cell drillings have Walls which allow radiation from onlya small portion of the pattern surface to be seen by each cell, and thedrillings may be lined with a polished material or have a smooth surfaceto prevent stray radiation reaching the photocells.

Each photocell is connected by wires 5 to an amplifier which in turnoperates a valve or relay controlling pattern making on the machine withwhich the device is associated.

At the upper end of the guide 13 a number of electric lamps 6 arelocated. The lamps have reflectors 7, and a filter 8 is located betweenthem and the light guide. This filter has a pass band for wavelengthsbetween 0.7 and 1.1 microns (7,000-11,000 Angstrom units), so that onlyinfrared radiation reaches the pattern and the photocells. The lightemitted by lamp 6 passes through the passage 9 of the radiationconductor 13 and is reflected from the pattern belt 1 back to thephotocells 4.

The pattern itself consists of an endless band made to a suitable scale.Its surface (FIG. 2) has areas 10 and 11, the area 10 being of smoothmaterial which has a high reflectivity coefficient for infraredradiation, and area 11 is of rough material, with a fibrous or brokensurface, have a low coeflicient. Surface 10 may be smooth white glazedpaper, and surface 11 may be crepe paper stuck on surface 10.

In order to ensure accurate action of the photocell devices for allkinds of pattern, we arrange one photocell so that it always views amaximum reflection band left at one end of the pattern. This photocellis conncted via a feed-back circuit to the current supply to the lamps,the circuit being such as to maintain a constant value of the reflectedradiation intensity, so that if a pattern is changed for another, or ifits maximum reflectivity changes with use, the illumination is adjustedto compensate for the change.

Although the invention has been described in connection with areflective pattern it should be understood that a pattern withtransmitting and opaque areas may be used, in which case it may bewrapped round a drum with the light source and filter located inside thedrum.

It is preferable to construct the lamp assembly as a separate unit andto provide a fan to move convected or conducted heat so that the patternreceives only radiated energy conducted along the guide 13.

What we claim is:

1. In a tufting machine for producing patterned fabrics comprising aplurality of needles each supplied with yarn, means for controlling saidsupply of yarn to said needles, said means being a pattern controllingdevice in cluding: a pattern moved synchronously with the material madeby the machine, and having infrared reflecting and absorbing areas, arow of lamps located to supply said pattern with infrared radiation,light guides positioned between said lamps and said pattern, filters forpassing only infrared radiation, positioned between said light guidesand said lamps, a plurality of infrared sensitive cells, means mountingsaid infrared sensitive cells in said light guides adjacent saidpattern, whereby infrared light passes through said light guides and isreflected from said 2. In a tufting machine as claimed in claim 1,infrared radiation-responsive cells being located so as to receiveradiation from a maximum radiation area of said pattern.

3. In a tufting machine as claimed in claim 1, in which said patternconsists of an endless band with smooth and rough pattern-definingareas.

References Cited UNITED STATES PATENTS 2,483,138 9/1949 Helmer.3,103,187 10/1963 Hammel 1l279 3,163,758 12/1964 Treacy. 3,166,6751/1965 Dedden et a1. 3,225,191 12/1965 Calhoun. 3,272,163 9/1966 Erwinet al. 112-79 3,323,103 5/1967 Shaw et a1.

infrared reflecting areas into said infrared sensitive cells. 20 JAMESR- B ER, Primary Examin r.

